Problem Description

Fix this GitHub issue on the unplugin-typia repo. There is an inconsistency in typia validation results between frontend and backend code in a Bun monorepo setup, where the same validation returns success:true in backend but success:false in frontend. The issue needs to be fixed by modifying configuration or the typia packages, without changing the application code in the common, frontend or backend packages.

Typia is a TypeScript runtime type validator and transformer similar to Zod that generates runtime validation code from TypeScript type definitions to ensure type safety at runtime.

Acceptance Criteria

An acceptable solution will:

• Output of all Typia validation functions must be the same in both frontend and backend.
• Will not modify common/index.ts
• Will not modify backend/index.ts
• Will not modify frontend/App.tsx
• May modify the following files to fix the issue:
  • Project configuration files for Typescript, Vite or Bun
  • unplugin-typia
  • typia

Technical Details

The issue occurs in a Bun monorepo setup where typia validation behaves inconsistently between frontend and backend code. The project structure consists of:

1. common package:

   • Contains shared TypeScript interfaces and types
   • Example data structures used across the app
   • Imported by both frontend and backend

2. frontend package:

   • React application using types from common
   • Uses typia for validation
   • Shows validation failing (success: false)

3. backend package:

   • Server application using same types from common
   • Uses typia for validation
   • Shows validation passing (success: true)

The validation inconsistency occurs when using typia's validateEquals function on the same data structure and type definition from the shared common package. The backend validation returns success: true while the frontend validation returns success: false, despite using:

• Identical type definitions from common
• Same version of typia
• Same example data structure
• Same validation function

The issue needs to be fixed by modifying configuration files or the typia/unplugin-typia packages, without changing the application code in common, frontend or backend packages.

Link to Project

https://github.com/mustpax/typia-bun-monorepo-vite-repro

Steps to Reproduce

1. Clone the repository:

   git clone https://github.com/mustpax/typia-bun-monorepo-vite-repro
   cd typia-bun-monorepo-vite-repro
   

2. Install dependencies:

   bun install
   

3. Start the development server:

   bun dev
   

4. Observe the validation results:

   • In the browser (frontend):

     • Open http://localhost:5173
     • Check browser console
     • Note validation shows success: false

   • In terminal (backend):

     • Check terminal output
     • Note validation shows success: true

5. Verify validation inconsistency:

   • Both frontend and backend use identical:
     • Type definitions from common/index.ts
     • Example data from common/index.ts
     • Typia validateEquals function
     • Yet produce different validation results

6. Key files to examine:

   • common/index.ts - Shared types and example data
   • frontend/src/App.tsx - Frontend validation
   • backend/index.ts - Backend validation
   • Project config files (tsconfig.json, vite.config.ts)